Importance of Achromatic Contrast in Short-Range Fruit Foraging of Primates

Trichromatic primates have a ‘red-green’ chromatic channel in addition to luminance and ‘blue-yellow’ channels. It has been argued that the red-green channel evolved in primates as an adaptation for detecting reddish or yellowish objects, such as ripe fruits, against a background of foliage. However, foraging advantages to trichromatic primates remain unverified by behavioral observation of primates in their natural habitats. New World monkeys (platyrrhines) are an excellent model for this evaluation because of the highly polymorphic nature of their color vision due to allelic variation of the L-M opsin gene on the X chromosome. In this study we carried out field observations of a group of wild, frugivorous black-handed spider monkeys (Ateles geoffroyi frontatus, Gray 1842, Platyrrhini), consisting of both dichromats (n = 12) and trichromats (n = 9) in Santa Rosa National Park, Costa Rica. We determined the color vision types of individuals in this group by genotyping their L-M opsin and measured foraging efficiency of each individual for fruits located at a grasping distance. Contrary to the predicted advantage for trichromats, there was no significant difference between dichromats and trichromats in foraging efficiency and we found that the luminance contrast was the main determinant of the variation of foraging efficiency among red-green, blue-yellow and luminance contrasts. Our results suggest that luminance contrast can serve as an important cue in short-range foraging attempts despite other sensory cues that could be available. Additionally, the advantage of red-green color vision in primates may not be as salient as previously thought and needs to be evaluated in further field observations

Activity patterns of Brachyteles arachnoides in the largest remaining fragment of Brazilian Atlantic Forest

Time is an important currency for primate energetics, reproduction, and survival. Here, we describe the activity budgets of a group of southern muriquis (Brachyteles arachnoides) inhabiting the largest continuous fragment of Brazilian Atlantic Forest (210,000 ha) in Parque Estadual Carlos Botelho (24°44´–15´S, 47´ 46–10 W), in the southern region of São Paulo State. We collected instantaneous scan sampling data to assess monthly, seasonal, and between-year differences in time allocation for the different activities for 2 complete, nonconsecutive years—1995 and 2002—and compare these with measures of food availability. Over the 2 yr, the group rested on average for 48%, fed for 28%, traveled for 22.5%, and socialized for 1.5% of daylight hours. On a monthly basis, resting correlated negatively with traveling in 1995, and strongly negatively correlated with feeding for both years. Feeding correlated negatively with traveling in 2002, with significantly more time spent traveling during periods of higher young leaf availability. Season was a major influence on activity: the group rested more during the hotter, rainy austral summer season, whereas feeding occurred more frequently in the cooler, drier winter season. We found no consistent associations between food availability and the time that southern muriquis spent in most activities. We suggest that these southern muriquis, like many other large-bodied and atelin primates, minimize energy expenditure while maximizing energy intake, which may be associated with their ability to be folivorous when their preferred fruit foods are less available. They thus adopt a flexible energetic strategy for coping with variable climatic conditions rather than being constrained by food availability

Encapsulation of α-cyano-4-hydroxycinnamic acid into a NaY zeolite

The authors are thankful to Dr. K. Biernacki for DFT calculations and Dr. A.S. Azevedo for collecting the powder diffraction data.The faujasite zeolite structure was studied to investigate its suitability for development of new drug delivery systems (DDS). The sodium form (NaY) of the zeolite was used for encapsulation of a-cyano-4-hydroxy-cinnamic acid (CHC), an experimental anticancer drug used in colorectal cancer therapy. The DDS was prepared by diffusion in liquid phase of CHC as a guest in the void space of the host zeolite structure at pH 7.0. The molecular integrity of CHC in the encapsulation process was evaluated by proton nuclear magnetic resonance spectroscopy(1H NMR) and Ultraviolet–Visible spectroscopy (UV–Vis). The new drug delivery system, CHC@NaY, was characterized by Fourier transform infrared spectroscopy and UV–Vis, chemical analysis, powder X-ray diffraction, and Scanning electron microscopy. Analysis of the data of the drug alone and encapsulated in NaY show that CHC and the zeolite framework preserved their original structure. The effect of the zeolite and DDS on HCT-15 human colon carcinoma cell line viability was evaluated. The encapsulation of CHC significantly increased its potency.OM and RA are recipients of fellowships (SFRH/BD/ 36463/2007, SFRH/BI/51118/2010) from Fundacão para a Ciência e Tecnologia (FCT, Portugal).This study was supported by the Centre of Chemistry and Life and Health Sciences Research Institute (ICVS), University of Minho, Portugal, FCT (Portugal) through POCTI and FEDER projects (ref. POCTI-SFA-3-686) and by the FCT grant ref. PTDC/SAU-FCF/104347/2008, under the scope of ‘‘Programa Operacional Temático "Factores de Competitividade’’ (COMPETE) of ‘‘Quadro Comunitário de Apoio III’’ and co-financed by Fundo Comunitário Europeu FEDER